Heat sink



FIG. 1 is a front view of a first embodiment of a heat sink;

FIG. 2 is a rear view of the first embodiment of the heat sink;

FIG. 3 is a left view of the first embodiment of the heat sink;

FIG. 4 is a right view of the first embodiment of the heat sink;

FIG. 5 is a top view of the first embodiment of the heat sink;

FIG. 6 is a bottom view of the first embodiment of the heat sink;

FIG. 7 is a first perspective view of the first embodiment of the heat sink;

FIG. 8 is a second perspective view of the first embodiment of the heat sink;

FIG. 9 is a front view of a second embodiment of a heat sink;

FIG. 10 is a rear view of the second embodiment of the heat sink;

FIG. 11 is a left view of the second embodiment of the heat sink;

FIG. 12 is a right view of the second embodiment of the heat sink;

FIG. 13 is a top view of the second embodiment of the heat sink;

FIG. 14 is a bottom view of the second embodiment of the heat sink;

FIG. 15 is a first perspective view of the second embodiment of the heat sink; and,

FIG. 16 is a second perspective view of the second embodiment of the heat sink. 

CLAIM The ornamental design for a heat sink, as shown and described. 